ANALYSIS OF EXCITATORY SYNAPTIC ACTION IN PYRAMIDAL CELLS USING WHOLE-CELL RECORDING FROM RAT HIPPOCAMPAL SLICES
ANALYSIS OF EXCITATORY SYNAPTIC ACTION IN PYRAMIDAL CELLS USING WHOLE-CELL RECORDING FROM RAT HIPPOCAMPAL SLICES
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DOI：
10.1113/jphysiol.1990.sp017980
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发表时间：
1990-03-01
影响因子：
5.5
通讯作者：
SAH, P
中科院分区：
文献类型：
--
作者：
HESTRIN, S;NICOLL, RA;SAH, P
1.采用贴片电极和薄片全细胞记录技术研究了海马CA 1区兴奋性突触的药理学和生物物理学特性。2.兴奋性突触后电流（EPSC）有一个快成分和一个慢成分，快成分的幅值对电压不敏感，慢成分的幅值依赖于电压，负斜率电阻范围为-70 ~-30 mV。3.电压依赖性成分被N-甲基-D-天冬氨酸（NMDA）受体拮抗剂DL-2-氨基-5-膦酰基戊酸（APV; 50 μ M）消除，其对快成分没有影响。相反，快电压不敏感成分被对慢成分没有影响的非NMDA受体拮抗剂6-氰基-7-硝基喹喔啉-2，3-二酮（CNQX; 10 μ M）消除。4.在不加Mg ~（2+）的Ringer溶液中，NMDA组分的电流-电压关系在比1. 3 mM-Mg ~（2+）存在时大得多的电压范围内呈线性。5.在索马的超极化电压阶跃可关闭EPSC的NMDA成分。这种关闭的动力学被用来估计突触下膜的钳制控制速度以及与索马的电子距离。EPSC的动力学分析仅限于被判断为处于适当电压控制下的突触。6.对于那些接近于索马的突触，非NMDA组分的衰减时间常数（其对电压不敏感）的范围为4-8 ms。NMDA组分的上升时间为8-20 ms，衰减时间常数为60-150 ms。在强直后增强或应用佛波酯增加发射器释放期间，EPSC的两个组分增加到相似的程度。9.这些实验提供了在海马兴奋性突触的双受体机制的详细描述。此外，本实验还提供了一种估计突触输入电紧张距离的电生理学方法。
1. The pharmacological and biophysical properties of excitatory synapses in the CA1 region of the hippocampus were studied using patch electrodes and whole-cell recording from thin slices. 2. Excitatory postsynaptic currents (EPSCs) had a fast component whose amplitude was voltage insensitive and a slow component whose amplitude was voltage dependent with a region of negative slope resistance in the range of -70 to -30 mV. 3. The voltage-dependent component was abolished by the N-methyl-D-aspartate (NMDA) receptor antagonist DL-2-amino-5-phosphonovalerate (APV; 50 .mu.M), which had no effect on the fast component. Conversely, the fast voltage-insensitive component was abolished by the non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX; 10 .mu.M) which had not effect on the slow component. 4. In Ringer solution with no added Mg2+ the current-voltage relation of the NMDA component was linear over a much larger voltage range than in the presence of 1.3 mM-Mg2+. 5. The NMDA component of the EPSC could be switched off with a hyperpolarizing voltage step at the soma. The kinetics of this switch-off was used to estimate the speed of clamp control of the subsynaptic membrane as well as the electronic distance from the soma. The kinetic analysis of the EPSC was restricted to synapses which were judged to be under adequate voltage control. 6. For those synpases that were close to the soma the time constant for decay for the non-NMDA component, which was voltage insensitive, ranged from 4-8 ms. 7. The rise time for the NMDA component was 8-20 ms and the time constant for decay ranged from 60-150 ms. 8. During increased transmitter release with post-tetanic potentiation or application of phorbol esters, both components of the EPSC increased to a similar extent. 9. These experiments provide a detailed description of the dual receptor mechanism operating at hippocampal excitatory synapses. In addition, the experiments provide an electrophysiological method for estimating the electrotonic distance of synaptic inputs.